GroStar GS2 Soil pH Pen

Test the Root Zone Directly — No Slurry, No Guesswork

Pulling a sample, mixing a slurry, and waiting for it to settle just to get a soil pH reading is a workflow most growers would happily skip — especially when the result tells you about yesterday's root zone, not today's.

The GroStar GS2 skips that step entirely. Its impact-resistant spear glass tip — built 10 times stronger than a standard probe — pushes directly into soil, coco, or rockwool for an immediate in-place reading, backed by a Swiss LabSen sensor for lab-level accuracy.

A PTFE anti-clog ring keeps the junction clear of debris between uses, and the kit includes a cleaning brush and hole dibber so you can prep a clean test point and maintain the probe without extra tools.

Key Features & Benefits

• Measures pH and temperature directly in the root zone — lets you test soil, coco, rockwool, and nutrient solution without prepping a slurry.
• Impact-resistant spear glass tip, 10x stronger — pushes into growing media confidently without the fragility of a standard glass probe.
• Swiss LabSen spear soil pH probe — delivers lab-grade sensor accuracy in a design built specifically for solid media.
• PTFE anti-clog ring — keeps the junction clear of soil and debris so readings stay consistent over repeated use.
• IP67 waterproof rating — stands up to the moisture and mess that come with regular root-zone testing.
• Complete kit included — comes with pH 7 and pH 4 calibration solutions, KCL storage solution, cleaning brush, hole dibber, lanyard, and manual.

Who Should Use the GroStar GS2

The GS2 suits growers working in soil, coco, or rockwool who want direct, in-place pH readings from the root zone — without mixing slurries or relying on probes too delicate for solid media.

Choosing the Right GroStar Pen for Your Setup

GroStar's pen lineup is built around what you need to measure: the GS1 covers pH and temperature in solution, the GS2 adds a soil-rated spear probe for direct media testing, the GS3 reads EC/PPM and temperature, and the GS4 combines all of it in one 5-in-1 tool. If you grow in soil, coco, or rockwool, the GS2's spear tip is purpose-built for your medium.

Frequently Asked Questions

What media can the GS2 test?

It's built for direct readings in soil, coco, and rockwool, and it also reads pH and temperature in nutrient solution.

Why does it use a spear-tip probe instead of a standard glass bulb?

The impact-resistant spear glass tip is roughly 10 times stronger than a standard probe, letting it push directly into solid growing media without the fragility that limits typical pH electrodes.

What's included to help me test and maintain it?

It ships with pH 7 and pH 4 calibration solutions, a KCL storage solution, a cleaning brush, a hole dibber for prepping test points, a lanyard, and a manual.

How does the anti-clog ring help?

The PTFE ring keeps the probe junction clear of soil and debris between uses, helping readings stay consistent over time.

Is it waterproof?

Yes — it carries an IP67 waterproof rating, suited to the moisture that comes with regular root-zone testing.